All patients demonstrating clinical signs of generalised peritonitis and radiological evidence of intra-peritoneal free air (on erect chest radiograph or abdominal CT scan will be eligible for the study. Individual patient consent will be sought. They will be given intravenous fluids (standardised regime) and intravenous antibiotics (3rd generation cephalosporin and metronidazole). All patients will be given prophylaxis against deep vein thrombosis (compression stockings and low molecular weight heparin). When patients have received adequate fluid resuscitation they will proceed to theatre on an emergency basis.